The world is fast moving towards computerization and the current wave in IT is e-commerce. With all companies and business houses vying for a domain in the cyber world, the e-business applications are becoming more and more popular. A majority of these applications are business to business (B2B) in nature where buyers and sellers negotiate trade over the electronic media. A major problem faced in such cases is of cataloging the products and providing some universal method of categorizing them. The products are generally identified using product identification number and are classified in a hierarchial structure using codes. These are generally numeric codes, with different predefined levels used to classify things.
For example a hypothetical 3 digit 3 level code would look like:    1 0 0 Agriculture, hunting and related service activities    1 1 0 Growing of crops; market gardening; horticulture    1 1 1 Growing of cereals and other crops    1 1 2 Growing of vegetables, horticulture specialties and nursery products    1 1 3 Growing of fruits, nuts, beverage and spice crops    1 1 4 Growing of decorative plants    1 2 0 Farming of animals    1 2 1 Farming of cattle, dairy farming    1 2 2 Farming of sheep, goats, horses, asses and mules    1 2 3 Farming of swine    2 0 0 Mining    2 1 0 Oil and gas extraction    2 1 1 Crude petroleum and Natural Gas Extraction    2 1 2 Natural Gas Liquid Extraction    2 1 3 Mining (except oil and gas)    2 2 0 Coal Mining    2 2 1 Bituminous Coal and lignite surface mining    2 2 2 Bituminous Coal underground mining    2 2 3 Anthracite Mining
Currently, there are a variety of codes available on the internet that classify products and services which can be used by applications:—Harmonic, NACE, NAFTA are a few popular ones. However, there is no code, which is exhaustive and completely covers all domains of services and products. One caters to services, the other to products, one caters to the IT industry, another to manufacturing. For example, the Harmonic code, which is the most widely used code (used majority of applications and by trade opportunities sites) does not have the product category ‘Computer’ in it. Probably when it was created, computers were not popular.
Forming new codes is an option but customers are already used to some universal codes and refrain from using a new set of codes. This approach also prevents integration of such applications with other existing applications and with those of business partners. It also leads to confusion amongst the buyers and sellers.
The above scenario necessitates the use of more than one of the available codes and the ability to use or choose from any of them. This presents the following problems:                codes differ from each other so much that it is not possible to define common template for all of them in the current form.        the number of digits in the codes are different. For example, Harmonic Codes are 6 digit codes, NACE are 4 digit and NAFTA/NAICE are 6 digit ones.        the number of levels in the hierarchy of codes vary. For example, Harmonic Codes have 3 levels, NACE have 3 levels and NAICE/NAFTA have 5 levels.        the number of digits in each level vary. For example in Harmonic Codes each level is 2 digits, in others it is not.        the number of digits in different levels of the same codes vary. For example in NACE codes, first level is 2 digits, while the second and third are 1 digit each. Similarly, in NAICE/NAFTA codes the first level is 2 digits and the next 4 levels are 1 digit each. So the Harmonic codes are 6 digit 3 level {2,2,2}, NACE codes are 4 digit 3 level codes {2,1,1}, NAFTA codes are 6 digit 5 level codes {2,1,1,1,1}.        
These problems drive the need for a generalized method to implement all codes, without difficulty and minimum effort for implementing applications over them. The method should be valid for any code and every code, for one code and any number of codes, together as well as separately.
The object of this invention is to provide a simple and effective system for enabling the storage and use of diverse classification systems in an integrated manner. The invention further not only caters to Product codes but can be used in any application where objects need to be classified in a hierarchy, for example, file systems, computer trees, users and user groups, industry segments.